Do you experience any unnecessary anxiety ? for example: you are sitting on a chair in a park and you are reading a book, when someone walks by you (especially when a person walks by you and you are sitting with your back facing that person) you would feel disturbed, you feel the urge to turn your body and take a look at that person, you feel a little uneasy and even a mysterious anxiety arise in your mind.
Why is this? Is this normal?